Wellhead apparatus



March 2, 1965 c. M. COLE ETAL 3,171,489

WELLHEAD APPARATUS Filed May 3, 1962 3 Sheets-Sheet 1 Fig.4

INVENTORS CHARLES M- COLE. PAUL E. BICKEL. BYWILL/AM w W020, .112.

March 2, 1965 PAUL, BY WILLIAM w W020, J/z

United States Patent 3,171,489 WELLHEAD APPARATUS Charles .M. Cole,Dunnville, Ontario, Canada, Paul E. Biclrel, Villa Park, Ill., andWilliam W. Word, .lr., Houston, Tex., assignors, by direct and mesneassignments, to Armco Steel Corporation, Middletown, Ohio, a corporationof ()hio Filed May 3, 1962, Ser. No. 192,174 8 Claims. (Cl. 166-665)This invention relates to well head apparatus and, more particularly, toan improved well head construction especially adapted for installationswhere cementing operations are to be carried out after an internalelement of the well head, such as a hanger member, has been installed.

In some applications, it is desirable to accomplish cementing of astring of pipe in a well after that string has been suspended in themanner in which it will remain during operation of the well. Thus, forinstance, it is desirable in some cases to first completely run in andsuspend a string of production casing, with the casing supported fromthe well head by the hanger member which is to remain in the well headduring operation of the well, and then to cement the production casing.Cementing is ordinarily accomplished by pumping the cement compositionthrough the casing string, an operation which causes well fluid to risein the annular space surrounding the string of easing. Since the hangermember from which the casing string is suspended is sealed both to thecasing and to the surrounding well head structure, some provision mustbe made for escape of the rising fluid around the casing string. Suchfluid flow could, of course, be permitted by displacing the hangermember upwardly in the well head, but this is an unsatisfactory solutionbecause, for example, it requires timeconsuming manipulation of the wellhead parts.

A general object of the invention is to provide a well head constructioncapable of allowing upward escape of fluid through an internal member,such as a hanger member, after that member has been finally installed insealed relation with respect to the surrounding well head structure.

Another object is to provide a valve-equipped well head member.

A further object is to provide a well head construction of the typedescribed embodying valve means which can be operated from a remotepoint above the well in order to selectively open and close flow ductsthrough one of the internal well head elements.

In order that the manner in which these and other objects are attainedin accordance with the invention can be understood in detail, referenceis had to the accompanying drawings, which form a part of thisspecification, and wherein:

FIG. 1 is a vertical sectional view of a well head apparatus inaccordance with one embodiment of the invention;

FIGS. 2, 3 and 4 are transverse sectional views on lines 2-2, 3-3 and44, FIG. 1, respectively; and

FIG. 5 is a fragmentary vertical sectional view of a portion of theapparatus of FIG. 1, illustrating the manner in which latch membersemployed therein are disengaged.

Turning now to the drawings in detail, it will be seen that theembodiment of the invention here illustrated comprises a casing headbody member 1 provided with an upright passage 2 which accommodates ahanger member 3. Hanger member 3 has an upright bore 4 in which isdisposed a tubing string supporting element or mandrel 5. Lower endportion 6 of body member 1 is exteriorly threaded or otherwise suitablyadapted for attachment to the top of the last piece of surface casing(not shown).

ice

Top portion 7 of body member 1 is connected, as by external threads asshown, to the sub 8 carried at the bottom end of conductor casing 9.Bore 4 of hanger member 3 is interiorly threaded at its lower end andthere is secured therein the upper end of the last piece of productioncasing 10. Top portion 11 of hanger body 3 is externally threaded forattachment, by sub 12, to a handling joint 13. Supporting element 5 hasa vertical throughbore 14 which is threaded at both ends, the last joint15 of the tubing string being secured in the lower threaded portion ofbore 14 and any suitable flow device 16 being secured in the upperthreaded portion of bore 14. Near its mid-point, passage 2 has a portionof reduced diameter, providing an upwardly facing, downwardly andinwardly tapering, frusto-conical seat 17. At its bottom end, hangermember 3 is formed with a downwardly facing, downwardly and inwardlytapering, frusto-conical surface 18 adapted to engage seat 17 inface-to-face contact, so that the hanger member can be securelysupported by body member 1. Above seat 17, portion 19 of passage 2extends as a right cylindrical surface interrupted only by a transverseannular groove 20. Opening inwardly of the body member 1, groove 20 hasa flat top wall 21 lying in a plane at right angles to the axis ofpassage 2. The upper end portion of passage 2 is enlarged, taperingupwardly and outwardly at 22.

Above surface 18, hanger member 3 has a right cylindrical outer surfacewhich is of such length that, when the hanger member is engaged withseat 17, the body of the hanger member substantially completely fillsthe space enclosed by cylindrical portion 19 of passage 2, as will beevident from FIG. 1. Hanger member 3 also has an intermediate portionpresenting an outer surface of right cylindrical configuration indicatedat 23, the diameter of surface 23 being materially smaller than thediameter of cylindrical portion 19 of passage 2, so as to provide anannular space between hanger member 3 and portion 19 of passage 2 whenthe hanger member is seated as shown in FIG. 1. At a point which isaligned with groove 29 when surface 18 of hanger member 3 engages seat17, the hanger member is provided with an outwardly opening, radiallyextending, cylindrical bore 24. A latch pin 25 is slidably disposed inbore 24.

Latch pin 25 has a cylindrical body 26 which is shorter than the depthof bore 24 and which has an outer diameter of such size that the latchpin slidably engages the wall of bore 24. A guide pin 27 projectsupwardly into bore 24, being fixed to hanger member 3 and extendingradially with respect to the bore. Latch pin 25 is provided with alongitudinally extending guide slot 28 which opens outwardly andreceives guide pin 27, so that the latch pin 25 is retained in apredetermined orientation. In an area which, as a result of cooperationof guide pin 27 and slot 28, is maintained as an upper portion of latchpin 25, the latch pin is cut away to provide a horizontal flat surface29 and an upwardly and inwardly slanting cam, surface 30. Body 26 of thelatch pin is provided with an axially extending bore 31 whichaccommodates a helical compression spring 32, the effect of the springbeing to bias the latch pin outwardly relative to hanger member 3. Thebottom of the outer end portion of the latch pin is chamfered or cutaway to provide a downwardly and inwardly slanting surface, as indicatedat 33, so that the tip of the latch member is of such dimension, axiallyof hanger member 3, as to be accommodated within groove 20. The locationof bore 24, and the position of flat surface 29, is such that, whensurface 18 of hanger member 3 is engaged with seat 17, surface 29 of theguide pin is aligned in a plane just below the plane occupied by topwall 21 of the groove, so that the tip portion of the latch pin can moveoutwardly into the groove.

When hanger member 3 is inserted downwardly into passage 2, it will beunderstood that the tip of latch pin 25 projects radially outwardly fromthe hanger member to such an extent that, as the hanger member islowered, the tip of the latch pin will ride along frusto-conical portion22 of the passage, so that the latch pin iscammed inwardly. Furtherlowering of the hanger member causes the tip of the latch pin to ridealong cylindrical portion 19'of passage 2. As the hanger member isseated,

the tip of the latch pin passes below top wall 21 of groove 20, and thelatch pin snaps outwardly into the groove, so that surface 29 is engagedbelow wall 21 and the hanger member is latched in its seated position.

Bore 4 of hanger member 3 is also provided with a portion of reduceddiameter presenting an upwardly facing, downwardly and inwardlyslanting, frusto-conical seat 34. Above seat 34, the wall of bore 4extends as a plain cylinder. The lower portion of mandrel is of suchdiameter as to substantially completely fill that portion of bore4-above seat 34. At its lower end, mandrel 5 is provided with .adownwardly and inwardly tapering, frusto-conical surface 35 disposed toengage seat 34 in face-to-face contact for support of the mandrel onhanger member 3. The Wall of bore 4 is interrupted, above seat 34, by aninwardly opening transverse annular groove 36 having a flat top wall 37lying in a plane at right angles to the axis of the mandrel 5. Mandrel 5is provided with a radially extending, outwardly opening bore 38accommodating a latch pin 39 which is identical in all respect to latchpin 25. Thus,: latch pin 39 has an upwardly facing, horizontal, fiat tipsurface 40 disposed just below top 'wall 37 of; groove 36- when themandrel is engaged with seat 34. Latch pin 39 also has a downwardly andinwardly slanting lower tip surface 41 disposed to come into engagementwith the top of hanger member 3 as the mandrel is lowered shown.

' extendingcircularly and lying in a plane at right angles tothe' axisof the adaptor, .the axial length of the skirt being such that, when theadaptor has been completely made up on the hanger member, as shown, thetip of the skirt is located in the plane occupied by fiat surface 29 ofthe latch pin. It will be understood that the retrieving adaptor isengaged with the hanger member at a time when the hanger member occupiesthe seated position illustrated in FIG. 1 and is latched in place.Accordingly, as the retrieving adaptor isthreaded onto therhangermember, the tip of skirt 47 moves down wardly into engagement with camsurface 30 of the latch pin. Because of this engagement, continueddownward movement of skirt 47 causes the latch pin to be cammedprogressively inwardly until, when the adaptor has been fully installed,thelatch pin 25 occupies the position seen into the hanger member,surface 41 serving to cam the A latch pin 39 inwardly in bore 38 so thatthe tip of the latch pin can ride along the plain cylindrical upperportion of bore 4 until the mandrel is seated," whereupon the latch pinis spring-biased outwardly into engagement in groove 36 in the mannerhereinbefore described with reference to latch pin 25. A

FIG. 1 illustrates the hanger member 3 after it has been landed, bymanipulation of handling point 13, with the handling joint and sub 12still in place. For removal of handling joint 13, it is necessary thatthe threaded connection between sub 12 and the upper end portion ofhanger member 3 be disengaged and this, of course, can only beaccomplished by rotation of the handling joint while the hanger memberis held against rotation. To make this possible, a stop pin 44 isprovided, being driven into a suitable radially extending bore throughthe cylindrical wall of groove 20, the arrangement being such that thehead of the stop pin 44 substantially fills groove 20. Accordingly, ifthe hanger member 3, once being seated, rotates on its seat, latch pin25 will come into engagement with the headof stop pin 44 and. preventfurther rotation of the hanger member. It will thus be seen that thestop pin 44 coacts with latch pin 25 to hold the hanger member againstrotation and so enable the operators to unscrewthe handling joint. Astop lug 45 is welded in groove 36 to cooperate with latch pin 39,preventing rotation of mandrel 5, in the samemannerjust described.

FIG. 5 illustrates the manner in which latch pin 25 can be dis'engagedinorder to allow removal'of hanger member 3. For this purpose, thehandling string terminates in a retrieving adaptor 46 having internalthreads adapted to cooperate with the externally threaded upper portionof the hanger member. Retrieving adapter 46 also has a cylindrical skirt47 of such diameter as to closely embrace the intermediate cylindricalsurface 23 of the hanger member when the retrieving adaptor has beencompletely made up on the hanged member, as.

approximately. seated.

in FIG. 5 and is fully retracted from groove 20. With the latch pin inthisposition, hanger member 3 can now be Withdrawn upwardly from passage2, by manipulation ofthe handling string; It will be understood that asimilar, smaller retrieving. adapter (not shown) canbe engaged over thethreaded upper end 'of mandrel 5 in order to cause retraction of latchpin 39," in the same I manner just described.

the well, whether the hanger member and mandrel have been properlyseated.

In this connection, it will be understood-by those skilled in the artthat, as the production casing string is lowered, an obstruction may beencountered at a-time when the hanger member 3 is Movement of the string.downwardly thus stops, and it could be assumed that the hanger memberhas engaged seat 17. There is thus an ambiguity, insofar as thesituationappea'rs to the operators,. since the operators cannot tell'forcertain whether seating has beenaccomplished or an obstructionencountered. Under these circumstances, an upward strain applied to thehandling string will be opposed by engagement of surface 29 with the topwall 21 of groove 20 if the hanger member is actually properly seated'sothat the latch pin 25 is engaged in'groove 20. Such en-' gagement isobservable because the load applied via the handling string will be inexcess of the weight of the producting casing string. If, on the otherhand, hanger member'3 has not been properly seated, .then latchpin 25willnot be engaged in groove 20 and only the weight of the productioncasing. string will oppose the upward force applied to the handlingstring. The difference in loads existing for the two situations isobservable by the operators at their location remote from the well headand serves as a positive indication as to whether or not the hangermember is in fact seated properly in body member 1.. Latch pin 39servesin the samegeneral fashion to allow the operators to determinewhether or not mandrel 5 is properly seatedon the hanger member.

V The second function'servedby the latch pins is to I secure the hangermember and the mandrel positively in place against fluid pressuresexisting inthe well. Thus,

so long as latch pin 2-5is properly engaged in groove 20,

head construction is to be subjected to very high well pressures. Thus,two diametrically opposed latch pins can be employed, or three latchpins can be employed, with equal angular spacings therebetween.

Hanger member 3 is provided with a plurality of vertical flow ducts 4-8and a plurality of angularly spaced vertical bores 49, each bore 49having an upper portion 50 of larger diameter and a lower portion ofsmaller diameter. A plurality of bolts 51 extend downwardly each througha different one of the bores 49, the length of the bolts being suchthat, when the bolt heads engage the shoulder 52 between the upper andintermediate portions of the hanger member 3, the tips of the boltsproject well below bottom face 53 of the hanger member. A helicalcompression spring 54 is disposed about each bolt 51 in the largerdiameter bore portion 50, springs 54 being engaged between the bolt headand the shoulder at the bottom of bore portion 50 in each case.

Below hanger member 3, an annular movable valve plate 55 surroundscasing it). Plate 55 has a flat upper face 56 adapted to engage bottomface 53 of the hanger member, circular grooves 57 and 58, concentricwith the circular opening of the valve plate, being provided toaccommodate sealing rings 59 and 60, respectively. The radial spacingbetween grooves 57 and 58 is greater than the diameter of flow ducts 48and the ducts 48 are so located that, when valve plate 55 engages thehanger member, the lower ends of all of the ducts 48 are disposedbetween sealing rings 59 and 60 and therefore excluded fromcommunication with the annular space between the production and surfacecasings.

The threaded tips of bolts 51 are each engaged in interiorily threadedupwardly opening bores 61 in valve plate 55 so that the valve plate issuspended from the hanger member via the bolts. The lengths of bolts 51,and the normal or extended dimensions of springs 54, are such that,assuming that the bolts are free to move upwardly relative to the hangermember, the springs are effective to bring the valve platesimultaneously into engagement with the hanger member so that good sealsare accomplished by sealing rings 59 and 60.

From FIG. 1, it will be observed that the heads of bolts 51 are disposedimmediately adjacent to the upper portion ll of hanger member 3 to whichsub 12 is to be attached. The proportions of sub 12 are such that, whenthe same is fully made up on the hanger member, lower end face 62 of thesub is disposed at a point near shoulder 52, such point being well belowthe transverse plane occupied by the tops of the bolt heads when springs54 are relaxed. Hence, installation of sub 12 serves first to engage endface 62 with the heads of bolts 51 and then to force the boltsdownwardly until the bolt heads engage shoulder 52. and valve plate 55is spaced well between lower face 53 of the hanger member. With thevalve plate in this position, flow ducts 48 are open at their lower endsfor communication with the space between the production and surfacecasings. Ducts 43 are also open at their upper ends via the spacebetween shoulder 52 and end face 62 of sub 12, for communication withthe annular space between the conductor casing or riser 9 and thehandling string.

Accordingly, when the handling string is manipulated to land the hangermember, flow ducts 48 are open and there is free communication betweenthe space between the production and surface casings, on the one hand,and the space between the conductor casing and handling string, on theother. So long as the handling string is left attached to the hangermember, engagement of end face 62 of sub 12 serves to maintain valveplate 55 in its open position so that flow ducts 48 remain open.Accordingly, before installation of mandrel 5 when the tubing string isrun in, cement can be pumped downwardly through casing 19 for cementingof the casing, Well fluid being free to pass upwardly between theproduction and surface casings, through ducts 48 in the hanger member,and then upwardly between the conductor casing and the handling string.When the cementing operation has been completed, removal of the handlingstring, with its sub 12, allows springs 54 to actuate valve plate 55 toits closed position.

Typically, the embodiment of the invention illustrated is useful inapplications where the well head is to be installed at the floor of ashallow body of water, the operation being carried out from a floatingvessel or fixed platform. Body member 1 is fixed to the top of the lastjoint of the surface casing and run down with sub 3 and conductor casingor riser 9 attached thereto as shown. With the surface casing stringcompleted, so that the body" member 1 is in its final position, hangermember 3 is then installed. Preliminarily, the hanger member is fixed tothe top of the last joint of production casing, and sub 12 is made up onthe top of the hanger member so that bolts Sl are depressed and valveplate 55 is in the open position seen in FIG. 1. The production casingstring, with the hanger member thereon, is now further lowered bymanipulating the handling joint until the string comes to a stop.Assuming that this occurs because of seating of the hanger member onseat 17, latch pin 25 will spring outwardly and engage the groove 20.That this has occurred can be determined by applying an upward force tothe handling string, as hereinbefore described. The production casing isnow cemented by pumping the cement composition down the productioncasing, well fluid being allowed to pass upwardly through the open flowducts 48 in the hanger member. Sub 12 is now retrieved by rotating thehandling string, causing latch pin 25 to come into engagement with stoppin 44 in groove 2%), so that the hanger member cannot rotate androtation of the handling string will unscrew the sub. Removal of thehandling string and sub 12 allows springs 54 to actuate valve plate 55to its closed position so that upward flow of fluid through flow ducts48 is then precluded. Latch pin 25, engaged in groove 20, act to preventupward displacement of the hanger member.

The well is now hydraulically fractured in conventional fashion. Mandrel5 is then attached to the last joint of the tubing string and a handlingjoint is made up on the top of the mandrel. The tubing string is thenlowered, the operator again observing when downward motion ceases.Assuming that lowering of the tubing string terminates because ofseating of the mandrel on seat 18, latch pin 39 will spring outwardlyinto groove 36, latching the mandrel in place. The operators again testfor seating by applying an upward strain on the handling string, ashereinbefore described. Further well completion steps can be carried outin conventional fashion.

A good fluid seal is established between hanger member 3 and thecyindrical wall portion 19 of passage 2 by a sealing ring 63 disposed inan outwardly opening transverse annular groove in the hanger memberimmediately above seat-engaging surface 18. A seal is provided betweenthe top of body member 1 and sub 3 by a sealing ring 64 disposed in adownwardly opening groove located in a portion of the sub opposed to thetop end face of body member 1, as seen in FIG. 1.

While one particularly advantageous embodiment of the invention has beenchosen for illustrative purposes, it will be understood by those skilledin the art that various changes and modifications can be made thereinwithout departing from the scope of the invention as defined in theappended claims.

What is claimed is:

1. In a well head construction, the combination of a body member havingan upright passage therethrough;

a support member adapted to be fixed to a string of pipe to be suspendedfrom the well head,

said support member being dimensioned for downward insertion into saidpassage, said body member and said support member having cooperatingshouldermeans engaged to supof said body member, and a lower annularspace,

surrounding the suspended pipe, when said support member is installedinsaid body member,

said support member having flow duct means extending upwardlytherethrough to communicate, when open, between said upper and lowerannular space;

movable valve means carried by said support member for movement betweena first position, in which it opens said fiow duct means and a secondposition, in which it closes said flow duct means; and V yieldable meansbiasing said movable valve means to said second position,

said movable valve means being so constructed and arranged as to presentan upwardly facing element for engagement from above said'support memberto actuate said movable valve means to said first position. 2. A wellhead construction in accordance with claim and wherein said supportmember is a casing hanger member having an upright bore forcommunication with the casing to be suspended therefrom,

annular sealing means being provided to seal between said hanger memberand' said body 7 member, 7 V said flow du'ct means extends through saidhanger member in at least one area located radially out: wardly fromsaid bore, and said movable valve means comprises an annular valvemember, and means vertically slidable in said hanger member and attachedto said valve member to suspend the same below said hanger member,

said valve member carrying upwardly facing sealing means disposed toengage said hanger member and establish a seal around said flow ductmeans. 1 t

3. A'well head construction in accordance with claim 2 and wherein 4. Awell head construction in accordance with claim 2 and wherein saidhanger member includes an upwardly said hanger memberimmediatelyltherebelow, said top portion joining the adjacent portion ofsaid hanger member at a transverse shoulder,

said hanger member being provided with a pluprojecting top portion ofsmaller'diameter than the portion of' rality of angularly spacedvertical bores extendsaid value member is in said second position,whereby said elongated elements can be depressed from above to move saidvalve member to said first position.

5; A wellhead construction in accordance with claim 4 and wherein saidtop portion of said hanger member is threaded for attachment toa'handling device, and

said elongated elements are so located as to be engaged and depressed bythe handling device when the latter is attached to said top portion.

6. In a well headapparatus, the combination of a body member having anupright passage thercthrough;

a hanger member having an upright bore for communicationwith a string ofpipe to be suspended from said hanger member, said hanger member havingat least one flow duet extending upwardly therethrough,

said hanger member being dimensioned for downward insertion into saidpassage,

said body and hanger members having cooperating shoulder means engagedto support said hanger member on said body member when said hangermember is inserted into said passage,

said hanger member being sealed in fluid-tight relation to the wall ofsaid passage when said shoulder means is engaged to support said hangermember,

said hanger member having at least one vertical bore therethroughoutwardly of said upright bore; 1

an elongated 'memberextending slidably through said vertical bore;

a movable valve member disposed below said hanger member and fixed tosaid elongated member, said valve member being engageable with saidhanger member to close said flow duct, said elongated'member projectingfreely above the upper end of said vertical bore when said'valve memberis engaged'with said hanger member;

and resilient means engaged between said elongated member and saidhanger member to bias said elongated member upwardly, whereby said valvemember is t biased to engage said hanger member and close said flowduct,

said elongated. member being engageable from above said hanger member,when said hanger member has been seated in said passage, for

depression against the biasing action of said resilient means, to movesaid valve member downwardly to open said flow duct,

7. In a well head construction adapted for underwater installation, thecombination of a tubular member having an upright passage therethrough;a hanger member having an upright bore for communication with a stringof pipe to be suspended from said hanger member,

said hangerrmem'ber being dimensioned fordownward insertion into saidpassage, said tubular member andsaid hanger member having cooperatingshoulder means engaged to support' said hanger member on said tubularmember when said hanger member is inserted into said passage, saidhanger member being sealed in fluid-tight relation to the wall of saidpassage when said shoulder means is engaged to support said hangermember, said hanger member having at least one flow duct extendingupwardly therethrough to communicate, when open, between the spaceabove. said hanger member and the space surrounding the string of pipebelow said hanger member; and valve means mounted on said hanger memberfor movement between a first position, in which it opens said flow duct,and a second position, in which it. closes said flow duct,

said valve means normally occupying one of said first and secondpositions, said hanger member having an upper portion of smallertransverse dimension than said passage, and said valve means includingat least one element which is located in the space between said upperportion of said hanger member and the wall of said passage and which isupwardly exposed, whereby remote actuation of said valve means from saidone of said positions to the other thereof can be accomplished by meansof an actuating tool moved downwardly to surround said upper portion ofsaid hanger member and operatively engage said upwardly exposed elementof said valve means. 8. In an underwater Well installation, thecombination of a head member having an upright passage therethrough; ahanger member having an upright bore,

said hanger member being dimensioned for downward insertion into saidpassage, said head member and hanger member having cooperating shouldermeans engaged to support said hanger member on said head member whensaid hanger member is inserted into said passage, said hanger memberbeing sealed in fluid-tight relation to the wall of said passage whensaid shoulder means is engaged to support said hanger member; a wellpipe fixed to said hanger member and depending therefrom,

said hanger member having an upright bore communicating with theinterior of said well pipe; conductor casing secured to said head memberand extending upwardly therefrom,

said hanger member having an upper portion spaced inwardly from saidconductor casing,

said upright bore extending through said upper portion;

a tubular member connected to said upper portion of said hanger memberand extending upwardly therefrom within said conductor casing,

said upright bore communicating with the interior of said tubularmember,

there being an annular space above said hanger member between saidconductor casing and said tubular member,

said hanger member having flow duct means extending therethroughoutwardly of said upright bore and communicating between the spaceoutside of said well pipe below said hanger member and said annularspace above said hanger member, whereby well fluid outside of said wellpipe can pass upwardly through said hanger memher and into said annularspace when said flow duct means is open; and

valve means mounted on said hanger member for movement between a firstposition, in which it opens said flow duct means, and a second position,in which it closes said flow duct means,

said valve means normally occupying one of said first and secondpositions,

said valve means including at least one upwardly exposed elementdisposed outwardly of said upper portion of said hanger member forengagement by an actuating tool carried by said tubular member, wherebysaid valve means can be actuated to the other of said positions bymanipulating said tubular member and tool from a location above andremote from said head member.

References Cited by the Examiner UNITED STATES PATENTS 2,080,610 5/37Humason l66-87 2,212,036 8/40 Otis 166-86 2,476,172 7/49 Williams285-317 X CHARLES E. OCONNELL, Primary Examiner.

1. IN A WELL HEAD CONSTRUCTION, THE COMBINATION OF A BODY MEMBER HAVINGAN UPRIGHT PASSAGE THERETHROUGH; A SUPPORT MEMBER ADAPTED TO BE FIXED TOA STRING OF PIPE TO BE SUSPENDED FROM THE WELL HEAD, SAID SUPPORT MEMBERBEING DIMENSIONED FOR DOWNWARD INSERTION INTO SAID PASSAGE, SAID BODYMEMBER AND SAID SUPPORT MEMBER HAVING COOPERATING SHOULDER MEANS ENGAGEDTO SUPPORT SAID SUPPORT MEMBER ON SAID BODY MEMBER WHEN SAID SUPPORTMEMBER HASA BEEN INSERTED INTO SAID PASSAGE. SAID SUPPORT MEMBER HAVINGA BODY PORTION SUBSTANTIALLY COMPLETELY FILLING SAID PASSAGE WHEN SAIDSUPPORT MEMBER IS DISPOSED WITH SAID SHOULDER MEANS IN ENGAGEMENT, ANDAN UPPER PORTION OF REDUCED TRANSVERSE CROSS SECTION DISPOSED ABOVE SAIDBODY PORTION, THERE BEING AN UPPER ANNULAR SPACE, SURROUNDING SAID UPPERPORTION OF SAID BODY MEMBER, AND A LOWER ANNULAR SPACE SURROUNDING THESUSPENDED PIPE, WHEN SAID SUPPORT MEMBER IS INSTALLED IN SAID BODYMEMBER, SAID SUPPORT MEMBER HAVING FLOW DUCT MEANS EXTENDING UPWARDLYTHERETHROUGH TO COMMUNICATE, WHEN OPEN, BETWEEN SAID UPPER ANDLOWERANNULAR SPACE; MOVABLE VALVE MEANS CARRIED BY SAID SUPPORT MEMBERFOR MOVEMENT BETWEEN A FIRST POSITION, IN WHICH IT OPENS SAID FLOW DUCTMEANS AND A SECOND POSITION, IN WHICH IS CLOSES SAID FLOW DUCT MEANS;AND YIELDABLE MEANS BIASING SAID MOVABLE VALVE MEANS TO SAID SECONDPOSITION, SAID MOVABLE VALVE MEANS BEING SO CONSTRUCTED AND ARRANGED ASTO PRESENT AN UPWARDLY FACING ELEMENT FOR ENGAGEMENT FROM ABOVE SAIDSUPPORT MEMBER TO ACTUATE SAID MOVABLE VALVE MEANS TO SAID FIRSTPOSITION.